1. Field of the Invention
The invention relates to a fastener-driving tool, more particularly to a powder-actuated fastener-driving tool.
2. Description of the Related Art
Referring to FIGS. 1 to 3, a conventional powder-actuated fastener-driving gun 1 is shown to include a housing 11, a barrel unit 12, a piston assembly 14, a sleeve 13, a holder 15, a spring-loaded firing pin 16, an L-shaped trigger plate 18, and an operating member 19.
The housing 11 has a front open end 111 and a rear end 112 opposite to each other in a direction (A).
The barrel unit 12 is inserted movably into the housing 11 via the front open end 111 of the housing 11.
The piston assembly 14 is disposed movably in the barrel unit 12. The sleeve 13 is coupled to a rear end of the barrel unit 12, and defines a chamber 131 for receiving gunpowder in the form of a load 9 therein. The holder 15 is disposed in the housing 11, abuts against the sleeve 13, and has a through hole 151.
The spring-loaded firing pin 16 is disposed in the housing 11 between the holder 15 and the rear end 112 of the housing 11, and has a thinner free end portion 161 extending into the through hole 151 in the holder 15, a thicker end portion 163 opposite to the free end portion 161 in the direction (A) and having a diameter larger than that of the free end portion 161, and an outer annular shoulder surface 162 disposed between the thinner free end portion 161 and the thicker end portion 163. The firing pin 16 is movable between a standby position, where a front tip of the thinner free end portion 161 of the firing pin 16 is spaced apart from the gunpowder in the chamber 131 in the sleeve 13, and a firing position, where the front tip of the thinner free end portion 161 of the firing pin 16 contacts and ignites the gunpowder in the chamber 131 in the sleeve 13, as shown in FIG. 3.
The trigger plate 18 is disposed in the housing 11 and adjacent to the holder 15, has a first plate portion 181 perpendicular to the direction (A) and formed with a through hole 180 permitting extension of the firing pin 16 therethrough, and a second plate portion 182 connected to one end of the first plate portion 181 and parallel to the direction (A). It is noted that, as shown in FIG. 2, the through hole 180 has a circular first hole portion 1801 having a diameter larger than that of the thicker end portion 163 of the firing pin 16, and a second hole portion 1802 having a diameter smaller than that of the thicker end portion 163 of the firing pin 16 and slightly larger than the thinner free end portion 161 of the firing pin 16. The trigger plate 18 is movable between a non-triggering position, where a part of the thinner free end portion 161 extends through the second hole portion 1802 of the through hole 180 in the first plate portion 181 and where the outer annular shoulder surface 162 abuts against an upper end of the first plate portion 181 of the trigger plate 18, as shown FIG. 1, and a triggering position, where the firing pin 16 extends through the first hole portion 1801 of the through hole 180 in the first plate portion 181 of the trigger plate 18, as shown in FIG. 3. As a result, when the trigger plate 18 is moved from the non-triggering position to the triggering position, the firing pin 16 is thus moved from the standby position to the firing position.
The operating member 19 is mounted pivotally on the housing 11, and is operable so as to drive the trigger plate 18 to move from the non-triggering position to the triggering position.
In use, prior to operation of the operating member 19, the firing pin 16 is maintained in the standby position since the outer annular shoulder surface 162 of the firing pin 16 abuts against the upper end of the first plate portion 181 of the trigger plate 18.
However, it is desired to design a power-actuated fastener-driving tool having a configuration different from that of the aforesaid conventional powder-actuated fastener-driving gun 1.